The 21-year-old CCSU student who was arrested on Monday after his Halloween costume triggered a campus-wide emergency and lockdown has been arrested again for returning to campus after he was warned to stay away, according to university police.

Police said David Kyem, a senior and son of CCSU geography professor Peter Kyem, had been asked not to set foot on campus until he had met with the school office of student Ccnduct. But around 1:15 p.m. on Tuesday, he was spotted around campus and in James Hall, the dormitory where he was first arrested.

Kyem is now charged with first-degree criminal trespassing. Yesterday, he was charged with breach of peace.

According to CCSU police, Kyem had been warned both verbally and in writing to stay away from the university campus until he had met with the school director of student conduct.

On Monday, the university released surveillance video and evidence photos from the three-hour police search, which started when students called 911 to report seeing a man with gun on the New Britain, Conn. campus.

Kyem was released yesterday after posting $1,000 bond.

The suspect's father, CCSU geography professor Peter Kyem, said the security incident was a misunderstanding caused by his son's Halloween costume.

He said his son had spent the weekend with a friend, attended a costume party the night before and was not in possession of any weapons. He doesn't think his son has ever held a gun.

"I think people saw him and mistook him for a gunman," Peter Kyem said. "They are all plastic materials, the mask and everything. ... It was a stupid thing he did."

David Kyem and two other people of interest were taken into custody yesterday.

CCSU President Jack Miller issued a statement on Tuesday saying that you can never be too vigilant or react too strongly to the threat of violence and that behavior that causes "widespread fear" won't be tolerated.

This is the full statement from President Miller:

"As further information unfolds from yesterday’s campus emergency incident, two observations have become clear to me about the world in which we now live.

"First, you can never be too vigilant nor react too strongly to the threat of violence. All potential threats must be taken very seriously, and the response must be a reaction to worst-case scenarios.

"Second, as an educational institution we must continue to educate our students and ourselves about the perception of threat. Behavior that causes widespread fear among our students and staff cannot and will not be tolerated."

David Kyem posted the following message on his Facebook page on Monday night:

"God bless everybody, stay positive and centered in love, not fear. Accidents and miscommunications happen but everything that happens in life is a blessing, a lesson or both. Just open your mind."

Kyem's suspicious appearance triggered a campus-wide lockdown. Police said 911 calls came in around noon as students reported a suspicious person who appeared to be armed. Listen to the first 911 call here.

"I saw a guy with camouflage pants, knee pads a body armor vest, paint ball mask with tinted goggles, and he had a Katana strapped to his back," CCSU junior Jordan Governale said. "Less than a minute after I saw him, as I was walking off campus, I saw seven or eight cop cars in the direction he was going in."

Witnesses said police were running with long guns shortly after arriving on campus, telling students to take cover. Officers from several agencies, including SWAT, the FBI and the Department of Homeland Security, swarmed the campus.

The lockdown lasted hours while police focused their investigation on James Hall, a dormitory where Kyem and two others were eventually taken into custody. Residents reported hearing an alarm go off and said police knocked on doors and told students who live on the first floor to evacuate to nearby halls.

Police said the three people of interest were apprehended on the fourth floor of James Hall, which houses more than 400 students.

"We ended up going floor by floor until we found the suspects," CCSU Police Chief Chris Cervoni said. "I believe all three were in the hallway, coming out of a room."

Police handcuffed Kyem, who was dressed in an orange shirt and camouflage pants, and escorted him from the building.

Authorities lifted the school lockdown shortly after 3 p.m. and gave students the all clear to leave the buildings where they'd been hunkered down. James Hall has reopened shortly thereafter.

Police said the building's ID card swipe system helped authorities track down the people they were looking for.

The other two people of interest haven't been identified, and it's not clear whether they are CCSU students. Cervoni said only that they are student-aged.

So far, Kyem is the only one who has been charged. Police are continuing to investigate.

All classes and events for Monday afternoon and night were canceled in light of the incident.

New Britain Mayor Tim O'Brien said no one was injured at the school that more than 10,000 students attend.

"I think this could happen anywhere so it just reinforced the idea that it's important to understand what the emergency guidelines are," said Kaylie Washburn, a senior at CCSU who said she rode the bus with the suspicious person and called police.

She said she was grateful for the quick police response and called 911 to "help prevent an incident like at Virginia Tech from happening at Central."

Holmes Elementary, at 2150 Stanley St., was on external lockdown out of an abundance of caution, Cooper said. Children are not going outside, but they can move around freely inside.

House of Arts Letters and Sciences Academy, or HALS, located at 30 Pendleton Road, is very close to campus and was on full lockdown.

The lockdowns at both schools have since been lifted.

"I want to commend state and local law enforcement for their quick response," said Conn. Gov. Dannel Malloy, in a statement. "While there was no act of violence today, the actions taken once these reports came in are exactly why it is so important to say if something if you see something. Unfortunately, incidents like these will occur, but today showed us the ideal way for them to conclude – with no one seriously harmed."